Battery management apparatus, battery management method, and battery pack

Abstract

There are provided a battery management apparatus, a battery management method and a battery pack. The battery management apparatus generates a first data set including a first current value, a first voltage value and a first temperature value indicating a current, a voltage and a temperature of a battery. The battery management apparatus generates a second data set from the first data set using an error generator. The battery management apparatus determines a first candidate value, a second candidate value and a third candidate value for a state of charge (SOC) from the first current value, the first data set and the second data set, respectively. The control unit determines the first candidate value or the second candidate value as the SOC based on a first difference value between the first candidate value and the second candidate value.

What is claimed is: 
     
       1. A battery management apparatus, comprising:
 a sensor circuit configured to detect a current, a voltage, and a temperature of a battery; and 
 a controller configured to:
 generate a first data set including:
 a first current value indicating the detected current; 
 a first voltage value indicating the detected voltage; and 
 a first temperature value indicating the detected temperature; 
 
 generate a second data set from the first data set using an error generator; 
 determine a first candidate value for a state of charge (SOC) of the battery, based on the first current value, using ampere counting; 
 determine a second candidate value for the SOC, based on the first data set, using an extended Kalman filter; 
 determine a third candidate value for the SOC, based on the second data set, using the extended Kalman filter; 
 determine a first difference value between the first candidate value and the second candidate value; 
 determine a second difference value between the first candidate value and the third candidate value; 
 determine the first candidate value as the SOC if the first difference value is larger than a threshold value; 
 increase a ratio of second process noise to first process noise of the extended Kalman filter above a predetermined reference ratio, if the second difference value is smaller than the first difference value; and 
 selectively output a switching signal to control a switch installed on a current path of the battery based on the first difference value and the second difference value. 
 
 
     
     
       2. The battery management apparatus according to  claim 1 , wherein:
 the second data set includes:
 a second current value; 
 a second voltage value; and 
 a second temperature value; and 
 
 the two values included in each of at least one of a first pair of the first current value and the second current value, a second pair of the first voltage value and the second voltage value, and a third pair of the first temperature value and the second temperature value are different from each other. 
 
     
     
       3. The battery management apparatus according to  claim 1 , wherein:
 the first process noise is associated with reliability of the ampere counting; and 
 the second process noise is associated with reliability of an equivalent circuit model of the battery. 
 
     
     
       4. The battery management apparatus according to  claim 3 , wherein:
 the controller is further configured to set a value that is smaller than a predetermined first reference value as the first process noise and a predetermined second reference value as the second process noise, if the second difference value is smaller than the first difference value; and 
 the reference ratio is a value obtained by dividing the second reference value by the first reference value. 
 
     
     
       5. The battery management apparatus according to  claim 3 , wherein:
 the controller is further configured to set a predetermined first reference value as the first process noise and a value that is larger than a predetermined second reference value as the second process noise, if the second difference value is smaller than the first difference value; and 
 the reference ratio is a value obtained by dividing the second reference value by the first reference value. 
 
     
     
       6. The battery management apparatus according to  claim 3 , wherein:
 the controller is further configured to set a value that is smaller than a predetermined first reference value as the first process noise and a value that is larger than a predetermined second reference value as the second process noise, if the second difference value is smaller than the first difference value; and 
 the reference ratio is a value obtained by dividing the second reference value by the first reference value. 
 
     
     
       7. The battery management apparatus according to  claim 3 , wherein the controller is further configured to determine the ratio of the second process noise to the first process noise in proportion to the first difference value, if the second difference value is smaller than the first difference value. 
     
     
       8. The battery management apparatus according to  claim 3 , wherein:
 the controller is further configured to set a predetermined first reference value as the first process noise and a predetermined second reference value as the second process noise, if the second difference value is equal to or larger than the first difference value; and 
 the reference ratio is a value obtained by dividing the second reference value by the first reference value. 
 
     
     
       9. The battery management apparatus according to  claim 1 , wherein the controller is further configured to determine the second candidate value as the SOC, if the first difference value is equal to or smaller than the threshold value. 
     
     
       10. The battery management apparatus according to  claim 1 , wherein the controller is configured to:
 regulate a duty cycle of the switching signal below a reference duty cycle, if the second difference value is smaller than the first difference value. 
 
     
     
       11. A battery pack comprising the battery management apparatus according to  claim 1 . 
     
     
       12. A battery management method, comprising:
 detecting a current, a voltage, and a temperature of a battery; 
 generating a first data set including:
 a first current value indicating the detected current; 
 a first voltage value indicating the detected voltage; and 
 a first temperature value indicating the detected temperature; 
 
 generating a second data set from the first data set using an error generator; 
 determining a first candidate value for a state of charge (SOC) of the battery, based on the first current value, using ampere counting; 
 determining a second candidate value for the SOC, based on the first data set, using an extended Kalman filter; 
 determining a third candidate value for the SOC, based on the second data set, using the extended Kalman filter; 
 determining a first difference value between the first candidate value and the second candidate value; 
 determining a second difference value between the first candidate value and the third candidate value; 
 determining the first candidate value as the SOC if the first difference value is larger than a threshold value; 
 increasing a ratio of second process noise to first process noise of the extended Kalman filter above a reference ratio, if the second difference value is smaller than the first difference value; and 
 selectively outputting a switching signal to control a switch installed on a current path of the battery based on the first difference value and the second difference value. 
 
     
     
       13. The battery management method according to  claim 12 , wherein:
 the second data set includes:
 a second current value; 
 a second voltage value; and 
 a second temperature value; and 
 
 the two values included in each of at least one of a first pair of the first current value and the second current value, a second pair of the first voltage value and the second voltage value, and a third pair of the first temperature value and the second temperature value are different from each other. 
 
     
     
       14. The battery management method according to  claim 12 ,
 wherein the first process noise is associated with reliability of the ampere counting, and 
 wherein the second process noise is associated with reliability of an equivalent circuit model of the battery. 
 
     
     
       15. The battery management apparatus method to  claim 14 , further comprising:
 setting a value that is smaller than a predetermined first reference value as the first process noise and a predetermined second reference value as the second process noise, if the second difference value is smaller than the first difference value, 
 wherein the reference ratio is a value obtained by dividing the second reference value by the first reference value. 
 
     
     
       16. The battery management method according to  claim 14 , further comprising:
 setting a predetermined first reference value as the first process noise and a value that is larger than a predetermined second reference value as the second process noise, if the second difference value is smaller than the first difference value, 
 wherein the reference ratio is a value obtained by dividing the second reference value by the first reference value. 
 
     
     
       17. The battery management method according to  claim 14 , further comprising:
 setting a value that is smaller than a predetermined first reference value as the first process noise and a value that is larger than a predetermined second reference value as the second process noise, if the second difference value is smaller than the first difference value, 
 wherein the reference ratio is a value obtained by dividing the second reference value by the first reference value. 
 
     
     
       18. The battery management method according to  claim 14 , further comprising determining the ratio of the second process noise to the first process noise in proportion to the first difference value, if the second difference value is smaller than the first difference value. 
     
     
       19. The battery management method according to  claim 14 , further comprising:
 setting a predetermined first reference value as the first process noise and a predetermined second reference value as the second process noise, if the second difference value is equal to or larger than the first difference value, 
 wherein the reference ratio is a value obtained by dividing the second reference value by the first reference value. 
 
     
     
       20. The battery management method according to  claim 12 , further comprising determining the second candidate value as the SOC, if the first difference value is equal to or smaller than the threshold value.